Resetting Test Database via rake test is complaining: "database configuration does not specify adapter"

Question

I am attempting to use this bit of useful code from this question:

namespace :db do 
  namespace :test do 
    task :reset do 
      ActiveRecord::Base.establish_connection('test')
      Rake::Task['db:drop'].invoke
      Rake::Task['db:create'].invoke
      Rake::Task['db:migrate'].invoke
      ActiveRecord::Base.establish_connection(ENV['RAILS_ENV'])  #Make sure you don't have side-effects!
    end
  end
end

Unfortunately I am getting this error:

** Invoke db:test:reset (first_time)
** Execute db:test:reset
rake aborted!
database configuration does not specify adapter
/home/nick/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-   3.2.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:45:in `resolve_hash_connection'
/home/nick/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:39:in `resolve_string_connection'
/home/nick/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:25:in `spec'
/home/nick/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:127:in `establish_connection'
/home/nick/Projects/yumbin/lib/tasks/test_environment.rake:4:in `block (3 levels) in <top (required)>'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/home/nick/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/home/nick/.rvm/gems/ruby-1.9.3-p194@global/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>'
./bundler_stubs/rake:16:in `load'
./bundler_stubs/rake:16:in `<main>'
Tasks: TOP => db:test:reset

As you can see I am using Ruby 1.9.3 via RVM. I am using Rails 3.2.5, Rake version 0.9.2.2 and Postgresql 9.1, and the pg gem (0.13.2). Additionally, I have no database errors in my environments. Thhe app is deployed and running on Heroku, runs locally in development, and I can run my full test suite without issue. In a Rails console running the line:

ActiveRecord::Base.establish_connection('test')

succeeds. I checked the database.yml in vi for invisible characters but could not find any. Only '$' at the end of each line. I'm starting to think that the answer is incredibly simple and in front of my nose but I just can't see it.

UPDATE: Adding my database.yml file:

# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
development:
  adapter: postgresql
  encoding: unicode
  database: myapp-dev
  pool: 5
  username: ******
  password: *******

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  adapter: postgresql
  encoding: unicode
  database: myapp-test
  pool: 5
  username: *****
  password: ******

production:
  adapter: postgresql
  encoding: unicode
  database: myapp
  pool: 5
  username: ******
  password: *******

Answer 1

You need a test entry in your database.yml file, and I think you're probably lacking one. Make sure you have an entry that looks like this in database.yml:

test:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000

Using whatever adapter and database your development database is using.